… frequent cases with performance problems with MySQL is what they happen every so often or certain times. Investigating them we find out… cause is some batch jobs, reports and other non response time critical activities are overloading the system causing user experience to… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing…
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 5 Comments
… automatically. Making this change I could bring optimization, and full query execution time to less than 50ms. Low values, such as 3,4… think faster execution plan computation would be more important than backward compatibility. In MySQL 5.6 things are likely to get even better…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…certain times which I may be able to correlate to some events ? If you can’t get …query execution, which size can be controlled by tmp_table_size and which also only exist for duration of query execution… can do better as you can query temporary tables too: mysql> select sum(data_length+index_length…
Comment: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 22, 2012 By 10 Comments
Thanks for interesting results! The variation in query execution plans is probably a result of variation in InnoDB statistics. … can do about that. In MySQL 5.6 you can use InnoDB Persistent Statistics to get stable statistics and plan stability. (See… statistics. (See http://oysteing.blogspot.com/2011/04/more-stable-query-execution-time-by.html)
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…query blocks any READ queries to execute on the table. mysql> show processlist; +——-+——+———–+———-+————+——+——————————+——————————+———–+—————+———–+ | Id | User | Host | db | Command | Time…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
… the original query execution time. It may be possible, therefore, to refresh an MV based on a query that takes 45 minutes to execute with… about of time: mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'complete_example2′)); Query OK, 0 rows affected (42 min 42.14 sec) mysql> call…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…queries. Following that there are summaries of various data points such as the total query execution time and the average query execution time…queries that you can use to gather more data about the underlying tables involved and the query execution plan used by MySQL…
Post: Logging MySQL queries from the client instead of the server
February 2, 2011 By 2 Comments
…query log” is the single most valuable way to examine query execution on your MySQL server. Queries are logged with timing…see both views of query execution time. Why would you want to see the query timing information from the… server was so overloaded that nobody could get into it if they wanted to. …
Post: What is exec_time in binary logs?
January 31, 2011 By 2 Comments
…MySQL‘s mysqlbinlog tool, you’ve probably seen something like the following in the output: “exec_time=0″ What is the exec_time…query‘s execution time, but it is not. In most cases, the exec_time will be similar to the query execution time on the server where the query…
Post: What do we optimize with mk-query-digest ?
December 15, 2009 By 2 Comments
… at mk-query-digest report we typically look at the Queries causing the most impact (sum of the query execution times) as well as queries having… however perfectly possible to get bad performance with MySQL responsible for large portion of response time without any slow queries. We’ve seen pages…
